Various methods are proposed for facilitating input-output impedance matching for an amplification device that amplifies a high frequency. In addition, for a higher efficiency of the amplification device, impedance matching of harmonics is performed in addition to impedance matching of a fundamental wave.
As an example, the impedance matching of the fundamental wave and the harmonics may be performed by a matcher including a transmission line coupled to an output electrode of an amplifier and an open stub having one end coupled to this transmission line. However, in this case, harmonic processing may not be performed in an excellent manner.
The followings are reference documents.
[Document 1] Japanese Laid-open Patent Publication No. 9-289365,
[Document 2] Japanese Laid-open Patent Publication No. 9-252207, and
[Document 3] Japanese Laid-open Patent Publication No. 63-119307.